1. Field of the Invention
The present invention relates to method for scrolling MPEG-compressed pictures.
2. Brief Description of the Background of the Invention Including Prior Art
In many cases it is necessary to display pictures on a screen, in order to show products or to present various images or texts containing information, for instance, about train departures and arrivals. In existing technology, displaying new information and showing a new picture has consisted in the removal of earlier information from the screen and substituting it with a new one. This procedure does not provide for the possibility of simultaneous viewing and comparison of information or pictures, or the possibility of partial clearing of picture or text, in order to substitute this part with a new picture or text.
An example of a procedure which allows viewing a picture which is larger than a standard MPEG picture in length or width is described in the U.S. Pat. No. 5,867,208. In the preferred embodiment, an interactive television system comprises a video delivery system for providing video content, and at least one subscriber television set including a display screen. The subscriber television set is coupled to the video delivery system. The video delivery system provides a compressed picture, which is subdivided into slices and possibly groups of slices such that the image may be scrolled smoothly. The subscriber television set receives the compressed picture and operates to scroll in the compressed picture as desired by the user.
Another method is described in the U.S. Pat. No. 5,208,588. A picture which is larger than a standard picture is scrolled continuously by removing lines at the bottom of the screen and inserting lines at the top of the screen, or inversely. This procedure does also not allow to compare the content of the selected picture with the content of another one.